A sample processing apparatus for aspirating a sample, such as blood or urine, accommodated in a sample tube by an aspiration tube, and processing the sample is known.
Use of a sample processing apparatus for a long period of time may cause dirt accumulation in the fluid system such as the aspiration tube, flow path, valve, reaction tube, analyzing section, and the like. This may cause a deterioration of accuracy or an operation failure. The fluid system thus needs to be periodically washed after the apparatus completes operation or for every predetermined number of processing samples.
JP Laid-open Patent No. 2003-254980 discloses a specimen analyzer for aspirating washing fluid in a fluid tube with an aspirating section, and performing a washing of interior of fluid circuit. In this configuration, when a rack holding the washing fluid tube is set in the specimen analyzer, the set rack is transported. When the washing fluid tube held in the rack is recognized by the apparatus, the washing fluid is automatically aspirated from the washing fluid tube and the fluid circuit is washed.
The washing of the fluid circuit using the washing fluid includes filling a chamber, a detection unit, and a flow path connecting the same with the washing fluid, leaving it for a certain time to remove the dirt accumulated inside the chamber and the flow path. It takes a long time for performing a washing. Therefore, when performing the automatic washing using the washing fluid, it is preferred that the washing fluid is supplied to the sample processing apparatus after sample tubes are supplied to the sample processing apparatus and samples therein are processed by the sample processing apparatus.
However, if the sample tube and the washing fluid tube are set so that the washing fluid tube is supplied to the sample processing apparatus before the sample tube is supplied to the sample processing apparatus, the automatic washing will be started before the processing of the sample in the sample tube. In such case, the sample to be processed has to wait until the washing is completed.